CVE-2026-20329: Cisco Secure Firewall Adaptive Security Appliance ASA Software

Critical severity, CVSS 9.9. EPSS: 0.4% chance of exploitation in the next 30 days.

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense Software and Cisco Secure Firewall Management Center Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities.   The vulnerabilities tracked by CVE-2026-20329 are related to issues concerning improper handling of exceptional conditions that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-703.

Affected products

• Cisco Cisco Secure Firewall Adaptive Security Appliance ASA Software: version 9.16.1 only; version 9.16.1.28 only; version 9.16.2 only; version 9.16.2.3 only; version 9.16.2.7 only; version 9.16.2.11 only; …
• Cisco Cisco Secure Firewall Management Center FMC: version 7.0.0 only; version 7.0.0.1 only; version 7.0.1 only; version 7.0.1.1 only; version 7.0.2 only; version 7.2.0 only; …
• Cisco Cisco Secure Firewall Threat Defense FTD Software: version 7.0.0.1 only; version 7.0.1 only; version 7.0.1.1 only; version 7.0.2 only; version 7.0.2.1 only; version 7.0.3 only; …

Published 2026-09-16. Last modified 2026-09-18.